Wilkes University - (2026–2027) actual (PDF)
1. A 68-year-old patient with heart failure and atrial fibrillation is started on digoxin. The nurse
practitioner considers the patient's renal function because digoxin is primarily eliminated renally.
Reduced renal clearance prolongs which pharmacokinetic parameter, increasing the risk of digoxin
toxicity?
A) Volume of distribution
B) Hepatic metabolism
C) Elimination half-life
D) Protein binding
Correct Answer: Elimination half-life
Rationale: Digoxin is excreted predominantly unchanged by the kidneys. Reduced renal clearance
prolongs the elimination half-life, causing drug accumulation and increased toxicity risk. Volume of
distribution, hepatic metabolism, and protein binding are not primarily altered by renal impairment,
making C the correct answer.
2. A patient taking warfarin for atrial fibrillation is prescribed trimethoprim-sulfamethoxazole for a
urinary tract infection. The nurse practitioner recognizes this antibiotic will potentiate warfarin's
effect primarily through which mechanism?
A) Induction of CYP3A4, increasing warfarin metabolism
B) Displacement of warfarin from albumin and inhibition of CYP2C9-mediated metabolism
C) Inhibition of CYP2C9, which metabolizes the S-enantiomer of warfarin
D) Reduced absorption of vitamin K from the gut
Correct Answer: Inhibition of CYP2C9, which metabolizes the S-enantiomer of warfarin, resulting in
increased anticoagulant effect
Rationale: Trimethoprim-sulfamethoxazole inhibits CYP2C9, the enzyme responsible for metabolizing
the more potent S-enantiomer of warfarin. This inhibition leads to increased warfarin levels, elevated
INR, and bleeding risk. Displacement from albumin also contributes, but CYP2C9 inhibition is the
primary mechanism.
3. A patient is prescribed a medication with a high first-pass effect. Which route of administration
would most effectively bypass this effect to achieve higher systemic bioavailability?
,A) Oral
B) Sublingual
C) Intravenous
D) Intramuscular
Correct Answer: Sublingual
Rationale: The sublingual route allows direct absorption into the systemic circulation via the rich
venous network under the tongue, bypassing the portal circulation and hepatic first-pass metabolism.
Oral administration undergoes extensive first-pass metabolism. Intravenous administration also
bypasses first-pass but is invasive.
4. A drug has a volume of distribution (Vd) of 500 L and a clearance (CL) of 50 L/hr. Which statement
best describes the clinical significance of this Vd?
A) The drug is primarily confined to the plasma compartment
B) The drug is highly protein-bound
C) The drug is extensively distributed into tissues
D) The drug has a short elimination half-life
Correct Answer: The drug is extensively distributed into tissues
Rationale: A Vd of 500 L far exceeds total body water (~42 L), indicating extensive tissue distribution.
Drugs with large Vd are sequestered in tissues, have long half-lives, and are not easily removed by
hemodialysis. Highly protein-bound drugs typically have small Vd.
5. A patient with hypertension is started on a beta-blocker. Which receptor subtype is primarily
responsible for the drug's negative chronotropic effect on the heart?
A) Beta-1
B) Beta-2
C) Alpha-1
D) Alpha-2
Correct Answer: Beta-1
Rationale: Beta-1 receptors are predominant in the heart, where their stimulation increases heart rate
(chronotropy) and contractility. Beta-1 blockade produces negative chronotropic and inotropic effects.
Beta-2 receptors mediate bronchodilation and vasodilation.
, 6. A patient is prescribed a cholinergic agonist for postoperative ileus. Which receptor subtype
mediates the desired increase in gastrointestinal motility?
A) Nicotinic
B) Muscarinic
C) Alpha-1
D) Beta-2
Correct Answer: Muscarinic
Rationale: Muscarinic receptors (M3 subtype) in the gastrointestinal tract mediate smooth muscle
contraction and increased motility. Nicotinic receptors are at the neuromuscular junction and
autonomic ganglia. Alpha-1 and beta-2 receptors are adrenergic.
7. A 55-year-old male with hypertension and benign prostatic hyperplasia is started on doxazosin.
Which adverse effect is most important to monitor during initial therapy?
A) Reflex tachycardia
B) First-dose hypotension
C) Hyperkalemia
D) Bronchospasm
Correct Answer: First-dose hypotension
Rationale: Doxazosin is an alpha-1 blocker that causes significant vasodilation. First-dose hypotension,
with dizziness and syncope, is a well-known adverse effect, especially in patients also taking diuretics
or with volume depletion. Dosing at bedtime minimizes this risk.
8. A patient receiving an ACE inhibitor develops a dry cough. Which medication class can be
substituted to provide similar cardiovascular benefits without this adverse effect?
A) Calcium channel blocker
B) Angiotensin II receptor blocker (ARB)
C) Beta-blocker
D) Direct renin inhibitor
Correct Answer: Angiotensin II receptor blocker (ARB)
Rationale: ARBs block the angiotensin II receptor directly without affecting bradykinin metabolism,
unlike ACE inhibitors. Since the cough is mediated by bradykinin accumulation, switching to an ARB
typically resolves the cough while maintaining blood pressure and renal protective effects.